Supplemental Effect of Astaxanthin in Broodstock Diets on the Quality of Yellowtail Eggs
1997 年 63 巻 5 号 p. 816-823
詳細
1997 年 63 巻 5 号 p. 816-823
Different levels of pure astaxanthin (0, 20, 30, and 40 ppm) were supplemented in soft-dry pellets (SDP), in order to clarify the effect of this carotenoid on the quality of eggs and spawning performance of yellowtail. Three-yearold fish of average body weight 6.1kg were separatelyfed one of each test diet. The feeding experiment was carried out in cages for about 5 months prior to spawning. Seven males and 7 females from each test diet group were transferred to 65m3 indoor spawning tanks to permit them to spawn spontaneously, while those which remained in the cages were artificially inseminated. Fish of both spawning investigations were induced to maturity by HCG injection (600 IU/kg-fish).
When the brood fish were allowed to spawn spontaneously, those fed SDP supplemented with 30 ppm astaxanthin gave superior results for total production, quality of eggs and the final number of normal larvae. These observations were identical to those from the artificially inseminated group. Thus, the supplementation of astaxanthin in SDP was found to be effective for broodstock yellowtail and seemed to be optimal at around 30 ppm (30mg/kg-diet); beyond which the qualityof eggs diminished.
